mm/zsmalloc: simplify shrinker init/destroy
Structure zs_pool has special flag to indicate success of shrinker
initialization. unregister_shrinker() has improved and can detect by
itself whether actual deinitialization should be performed or not, so
extra flag becomes redundant.
[akpm@linux-foundation.org: update comment (Aliaksei), remove unneeded cast]
Link: http://lkml.kernel.org/r/1513680552-9798-1-git-send-email-akaraliou.dev@gmail.com
Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 683c065..e136a8e 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -46,6 +46,7 @@
#include <linux/vmalloc.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
+#include <linux/shrinker.h>
#include <linux/types.h>
#include <linux/debugfs.h>
#include <linux/zsmalloc.h>
@@ -257,11 +258,7 @@ struct zs_pool {
/* Compact classes */
struct shrinker shrinker;
- /*
- * To signify that register_shrinker() was successful
- * and unregister_shrinker() will not Oops.
- */
- bool shrinker_enabled;
+
#ifdef CONFIG_ZSMALLOC_STAT
struct dentry *stat_dentry;
#endif
@@ -2324,10 +2321,7 @@ static unsigned long zs_shrinker_count(struct shrinker *shrinker,
static void zs_unregister_shrinker(struct zs_pool *pool)
{
- if (pool->shrinker_enabled) {
- unregister_shrinker(&pool->shrinker);
- pool->shrinker_enabled = false;
- }
+ unregister_shrinker(&pool->shrinker);
}
static int zs_register_shrinker(struct zs_pool *pool)
@@ -2426,11 +2420,13 @@ struct zs_pool *zs_create_pool(const char *name)
goto err;
/*
- * Not critical, we still can use the pool
- * and user can trigger compaction manually.
+ * Not critical since shrinker is only used to trigger internal
+ * defragmentation of the pool which is pretty optional thing. If
+ * registration fails we still can use the pool normally and user can
+ * trigger compaction manually. Thus, ignore return code.
*/
- if (zs_register_shrinker(pool) == 0)
- pool->shrinker_enabled = true;
+ zs_register_shrinker(pool);
+
return pool;
err:
